Safety apparatus



R. CHUTE SAFETY APPARATUS Aug. 12, 1969 Filed Oct. 13, 1967 3Sheets-Sheet l 3 Y N R 3 w W W w A A 0 H flw FIG .5

Aug. 12, 1969 CHUTE SAFETY APPARATUS 3 Sheets-Sheet 2 Filed Oct. 13,1967 FIG .5

INVENTOR. R/C'HARD CHUTE BY WZ% 7% f'M AT ORNEY-5 Aug. 12, 1969 R. CHUTE3,460,853

SAFETY APPARATUS Filed Oct. 15. 1967 I s Sheets-$heet 5 ,H N {5 5 f ignn //77 INVENTOR. RICHARD CHU TE A T TOR/V673 United States Patent SAFETYAPPARATUS Richard Chute, Huntington Woods, Mich., assignor to Eaton Yale& Towne Inc., Cleveland, Ohio, 21 corporation of Ohio Filed Oct. 13,1967, Ser. No. 675,133 Int. Cl. B60r 27/00; F17c 5/00 US. Cl. 280-150 22Claims ABSTRACT OF THE DISCLOSURE A container for pressurized fluids hasa relatively thin wall portion. Means, preferably in the form of anexplosive, is associated with the thin wall portion of the container andoperates to effect the formation of an opening in the relatively thinwall portion to provide for release of fluid from the container. Alinear flow distributor is associated with the container and distributesthe fluid flow substantially equally.

The present invention relates to apparatus for storing a high pressurefluid, and particularly relates to a container for storing high pressurefluid which is released to effect inflation of a confinement forprotecting an occupant of a vehicle during a collision.

Inflatable confinements for protecting an occupant of a vehicle during acollision are known. Such confinements are inflatable from a contractedposition to an expanded position. A fluid container is provided and isopened to provide for flow of fluid into the confinement. The fluid isreleased from the fluid container by an explosive which effects theformation of an opening in the wall of the container. Due to the factthat the pressures within the container are relatively high, thethickness of the walls of the container has been relatively great. Thethickness of the walls of the container has complicated the problem ofopening the container. Moreover, while diffuser members having aplurality of openings providing for fluid flow into the confinement atvarious locations are known, such flow has not been substantiallyuniform from each opening and the confinement has thus not been asuniformly inflated as desirable.

An important object of the present invention is the pro vision of a newand improved vehicle safety apparatus whcih includes an inflatableconfinement and a supply of fluid for inflating the confinement, andwherein the apparatus is constructed to operate reliably after asubstantial period of storage in the vehicle, is compact, and thus takesa minimum of space in the vehicle, and provides for substantiallyuniform inflation of the confinement within the necessary time toprotect a vehicle occupant during a collision.

Another important object of the present invention is the provision of anew and improved fluid pressure container for storing a fluid underpressure and which container may be readily opened to provide for fluidflow therefrom.

A more specific object of the present invention is the provision of afluid pressure container of substantial volume and containing a fluidunder pressure and which is constructed so as to have a relatively thinwall portion in which an opening may be readily formed to provide forrelease of fluid from the container.

A further object of the present invention is the provision of a new andimproved apparatus which includes a q from the opening.

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fluid pressure container having a fluid storage chamber of differenttransverse dimensions and wherein a relatively thin wall portion definesa portion of the chamber of a relatively small transverse dimension andmeans is associated with the thin wall portion to effect the formationof an opening therein to provide for flow of fluid from the storagechamber.

A still further object of the present invention is the provision of newand improved apparatus, as noted in the next preceding paragraph,wherein explosive means is associated with the relatively thin wallportion and is ignited to effect the formation of an opening in therelatively thin wall portion and as a result of the explosive beingassociated with the relatively thin Wall portion, the magnitude of theexplosive may be relatively small,

A further object of the present invention is the provision of a new andimproved apparatus including a fluid container and a diffuser memberassociated in such a manner that the size of the fluid container anddiffuser member as a unit may be maintained at a minimum andsubstantially uniform flow may be achieved through various openings inthe diffuser member.

Another object of the present invention is the provision of a new andimproved apparatus which includes a fluid container having meansassociated therewith to provide an opening in the container to providefor fluid flow therefrom, and the fluid flows from the opening and intoa chamber defined by a diffuser member and the container, and whereinthe diffuser member has a plurality of spaced discharge openingscommunicating with the chamber and the chamber has a cross-sectionaldimension proportional to the amount of fluid flow therethrough.

A still further object of the present invention is the provision of anew and improved apparatus including a fluid container and a diffusermember which, in part, encircles the fluid container and wherein anopening is provided in the fluid container and fluid flows from theopening into a chamber which tapers so as to provide a decreasedcross-sectional flow area as the fluid flows away Another object of thepresent invention is the provision of a new and improved apparatus whichincludes a container having a chamber therein for storing fluid underpressure and wherein the container has a relatively thin wall portionwhich is opened by an explosive means to provide for the flow of fluidfrom the chamber, and wherein the probability of circumferential tearingof the walls of the container is minimized.

A still further object of the present invention is the provision of newand improved apparatus which includes a pressurized container having achamber with a relatively thin wall portion, and wherein explosive meansis utilized for effecting formation of an opening in the relatively thinwall portion to provide for release of fluid from the chamher and whichincludes means for constraining the wall portions of the container tolimit tearing thereof and thereby control the size of the opening in thecontainer.

Further objects and advantages of the present invention will be apparentto those skilled in the art to which it relates from the followingdetailed description of preferred embodiments thereof made withreference to the accompanying drawing and in which:

FIG. 1 is a schematic view illustrating a safety device for a vehicleembodying the present invention;

FIG. 2 is a sectional view, taken approximately along the section line2-2 of FIG. 1, and with parts omitted;

FIG. 3 is an enlarged fragmentary elevational view of a portion of theapparatus shown in FIG. 2;

FIG. 4 is a sectional view, taken approximately along the section line4-4 of FIG. 3;

FIG. 5 is an enlarged fragmentary sectional view, partially inelevation, of the apparatus shown in FIG. 2;

FIG. 6 is an enlarged fragmentary sectional View of another portion ofthe apparatus shown in FIG. 3;

FIG. 7 is a view of a modified form of the present invention;

FIG. 8 is a view of a further modified form of the present invention;and

FIG. 9 is a sectional view, taken approximately along section line 1010of FIG. 9.

The present invention provides an improved fluid supply including acontainer for storing a pressurized fluid and which may be readilyopened to provide for release of fluid therefrom. The container may beutilized in association with different devices which utilize the fluidstored within the container. For purposes of illustration, the containeris shown as incorporated in a safety apparatus for protecting anoccupant of a vehicle, such as a truck, an automobile, or airplane,during a collision.

Referring to FIG. 1, a vehicle 10 is shown in the form of an automobilehaving a fluid supply 11 supported in the dashboard thereof in asuitable manner. The fluid supply 11 is associated with a confinement 12which has a collapsed condition located in the dashboard of the vehicle10 and which is inflated to an expanded condition as shown in dot-dashlines in FIG. 1. The confinement 12 is inflated by the fluid containedin the fluid supply 11. The fluid is released from the fluid supply 11in response to a collision condition being experienced by the vehicle10, and the confinement 12 is rapidly inflated to restrain and controlthe movement of an occupant of the vehicle relative to the dashboard ofthe vehicle as a result of the collision. The confinement 12 could beutilized in other locations in the vehicle 10, such as in the back ofthe front seat for protecting rear passengers, or in any other suitablelocation.

As shown in FIG. 2, the fluid supply 11 comprises a container 15 havingwall means defining a closed fluid chamber 16. The fluid container 15and chamber 16 has, what may be termed, an hour-glass shape. Morespecifically, the chamber 16 has spaced frusto-conical chamber portions17, 18. The frusto-conical chamber portions 17, 18 are interconnected bya substantially cylindrical chamber portion 19. The substantiallycylindrical chamber portion 19 has an internal diameter substantiallyequal to the smallest internal diameter of the frustoconical chamberportions 17, 18. The axes of the chamber portions 17, 18 and 19 lie on acommon line A-A, shown in FIG. 2. The narrow ends 17a and 18a,respectively, of the chambers 17 and 18, communicate with thecylindrical chamber 19. The wide ends 17b and 18b which are located atthe opposite ends of the container 15 are closed by spherical wall means22 and 23, respectively. A suitable fill valve, not shown, may beassociated with the container 15 for filling purposes.

In view of the fact that the transverse dimensions of the chamber 16vary, the thickness of the wall means defining the chamber 16 may alsovary. Those portions of the chamber 16 which have the greatesttransverse dimension have the greatest fluid forces acting thereon and,thus, must have the greatest wall thickness for strength purposes. As aresult, the thickness of the wall means 24, 25 defining thefrusto-conical chamber portions 17, 18, respectively, decreases as thetransverse dimension, namely, the diameter of the frusto-conical chamberportions, decreases. This should be particularly clear from FIG. 5wherein it can be readily seen that wall means 25 defining thefrusto-conical chamber portion 18 decreases in thickness as the wallmeans 25 extends toward the cylindrical chamber portion 19.

The substantially cylindrical chamber portion 19, in view of the factthat it has a relatively small transverse dimension or diameter, isdefined by a wall portion 30 which is relatively thin. In view of thefact that the wall portion 30 is relatively thin, an opening is morereadily formed therein to provide for flow of fluid from the chamber 16.Accordingly, means 40 for effecting the formation of an opening in thecontainer 15 is associated with the relatively thin wall portion 30defining the chamber portion 19.

The means 40 for effecting the formation of an opening in the relativelythin wall portion 30 may take many different forms. As illustrated inthe drawing, the means 40 preferably is explosive means. The explosivemeans illustrated comprises an explosive strip of material 41 which isshown schematically and preferably as a flexible linearshaped chargewhich, as is well known, is constructed to direct the explosive forcetoward the wall portion 30. Upon ignition of the explosive, a portion 42of the wall portion 30 opens, enabling the pressure of the fluid in thechamber 16 to force the portion 42 outwardly of the container 15 and inthe event that the explosive material 41 does not form a completecircle, the portion 42 will be bent outwardly to the position designated42a, as shown by dot-dash lines in FIG. 4, to thereby provide an openingfor the flow of fluid from the chamber 16.

The strip of explosive material 41 is ignited by a suitable igniting ordetonating explosive material 50, best shown in FIG. 6. The material 50is detonated by the flow of current through either a resistance wire 51or a resistance wire 52, both of which are positioned in the material50. The flow of current through both or either wire 51 or Wire 52results in detonation of the material 50 which, in turn, causesdetonation of the strip explosive 41. The explosive material 50 isassociated with the explosive strip 41 at two spaced locations X and Yand is adapted to ignite the explosive strip at both locations. In theevent that the strip 41 is not ignited at one of the locations X or Y,the strip 41 will still be ignited at the other location. This providesadditional assurance that the explosive strip 41 will be ignited andmakes the system extremely reliable.

Current flows through the wires 51, 52 upon closing of a switch 54 whichis connected across a suitable power source. The switch 54 may be closedupon the vehicles encountering a collision condition. The switch 54 maysense a collision condition being experienced by the vehicle or may bemanually actuated. The fact that a current flow through either wire 51or wire 52 effects ignition of the material 50 provides for a greaterprobability of actuation of the explosive 41 due to the fact that if oneof the resistances is in some manner shorted or broken, the other willstill efiect ignition of the material 50.

From the above, it should be apparent that when the switch 54 is closed,the strip material 41 is ignited, causing the area 42 of the wallportion 30 to be opened by the force of fluid in the chamber 19. Thefluid forces the area 42 to the position illustrated in FIG. 4, as notedabove, and rushes from the opening formed in the container 15. The fluidwhich is directed through the opening encounters a diffuser member orlinear flow distributor 60. The diffuser member or linear flowdistributor is substantially cylindrical in configuration and encirclesthe container 15. The flow distributor 60 is provided with a pluralityof slots 61. The fluid flowing from the chamber 16 flows through theslots 61 in the diffuser and into the confinement 12 to eflect inflationof the confinement.

In view of the fact that the wall portion 30 of the container 15 isrelatively thin, the explosive charge in the strip material 41 may berelatively small as compared to the size of an explosive which would berequired to form an opening in a relatively thick wall portion of thecontainer 15. Thus, the noise level upon ignition of the explosive 41 issubstantially lower than if more explosive were utilized as would berequired to provide an opening in the relatively thick wall means 25 ofthe container 15. Moreover, the overall volume of the container is notsacrificed and is sufliciently great so as to provide the desired amountof fluid flow into the confinement 12. This volume may be substantiallyin excess of the volume of the confinement 12, as discussed in copendingapplication Ser. No. 681,393 filed Nov. 8, 1967, of common ownershipwith the present application.

Upon ignition of the explosive strip 41, fluid flows through an openingformed in the wall portion 30 of the container 15. The fluid as it flowsthrough the opening flows into a chamber, generally designated 55,defined by the linear flow distributor 60 and the container 15. Due tothe shape of the linear flow distributor 60, the chamber 55 has atapered configuration as it extends from the central portion thereof inopposite directions toward the opposite ends of the chamber. Theopenings 61 in the linear flow distributor 60 are located at spacedlocations along the axial extent of the linear flow distributor 60 andintersect the chamber 55 at various locations. The tapered configurationof the chamber 55 is such that a substantially uniform flow of fluid isprovided from each of the openings 61 and a minimum pressure drop isexperienced between the central portion of the chamber 55 immediatelyadjacent the opening 61a and the opposite ends 55a, 55b of the chamber55. As

a result of the above-described construction, the flow through thevarious openings 61 in the linear flow distributor 60 is substantiallyequal.

Moreover, in view of the fact that the chamber 55 is constructed so asto provide a minimum pressure drop throughout, the size of the pressurecontainer 15 may be minimized and yet the confinement 12 may be readilyinflated uniformly and within the required time. The minimizing of thesize of the container 15 is important since the unit comprising thecontainer 15 and diffuser 60 is located in association with thedashboard of the vehicle and should not be of such size to interferewith other structures in the dashboard or with the comfort of thepassengers.

Furthermore, the flow of fluid from the chamber 16 through the openingformed in the wall portion 30 may be controlled by the dimension 65 ofthe chamber 16, as shown in FIG. 2. Fluid contained in thefrusto-conical chambers 17, 18 in order to flow from the container 15flows into the chamber 19. The fluid flows from the chambers 17, 18 at arate which is controlled by the size of the dimension 65 as long as theopening formed in the container 15 by the explosive 41 is sufficientlylarge. Thus, by controlling the dimension 65, the rate of flow of fluidfrom the frusto-conical chambers 17, 18 into the confinement 12 may becontrolled. The smaller the dimension 65, the more restricted the flowof fluid will be, and the larger the dimension 65, the more freely thefluid will flow. This rate of fluid flow control is important to preventrupture of the confinement 12 by an excessive fluid flow into theconfinement.

The relatively thick wall portions 24, 25 defining the frusto-conicalchamber portions 17, 18, respectively, control and minimize the tendencyof the material of the container 15 to tear when the container 15 isopened. The tearing of the material would provide an uncontrolled largeopening in the container 15 which may permit a substantial amount offluid to flow from the chamber 16 at a fairly rapid rate and may alsocause rupturing of the confinement 12. Thus, the thick wall portions 24,25 minimize the possibility of longitudinal tearing and assist incontrolling the fluid flow from the container 15.

A modification of the present invention is illustrated in FIG. 7. Thismodification includes means 40 in the form of a strip explosive 41 toeffect the formation of an opening therein, as described above inconnection with FIG. 3. The explosive strip 41 is mounted on a plate 71.The plate 71 is of a relatively thin wall construction and supports thestrip explosive between the plate 71 and the container 15. When theexplosive is ignited, the container 15 is opened and fluid rushesthrough the opening formed in the container. The plate 71 is eitherdestroyed or otherwise removed from the container due to the explosion.

The plate 71 is retained on the substantially cylindrical chamberportion 19 of the container 15 by bands 76, 77. The bands 76, 77 providenot only means for retaining the plate 71 on the container 15, but alsoapply a constraining force, constraining the diameter of the container15 and resisting expansion of the diameter of the container 15 uponignition of the explosive. As a result of this constraint, the strips76, 77 minimize circumferential tearing of the plate 71 and. thecontainer 15 upon ignition of the explosive 41. The specificconstruction is shown and described in more detail in application Ser.No. 664,822, assigned to the assignee of the present invention.

The embodiment illustrated in FIGS. 8 and 9 incorporates the structuraladvantages described hereinabove in connection with the embodimentsdescribed above. In the embodiment of FIGS. '8 and 9, the fluidcontainer 15 is associated with a diffuser member 60. The fluidcontainer is opened by an explosive actuating means 40. When theexplosive actuating means 40 is actuated, the fluid flows from thereservoir or container 15 and through the slots 61 in the diffusermember and into the inflatable confinement 12 illustrated in FIG. 1 toeffect inflation of the confinement 12.

The reservoir 15 is provided with a fill connection at one end thereofthrough which the reservoir 15 is filled with fluid. The reservoir 15 atthe other end thereof has a neck-down portion 101. The neck-down portion101 includes a projecting surface portion 102 which projects outwardlyfrom the body of the reservoir 15. A linearshaped strip of explosivematerial 103 encircles the projecting portion 101 of the reservoir .15in order to effect the formation of an opening in the reservoir 15 upondetonation thereof. The explosive strip 103 extends around the surface102 of the projecting portion 101 of the reservoir 15 and is ignited bythe passage of a current through a detonator 104. A current is directedthrough the detonator 104 by lead wires or conductors 105 which extendthrough an opening 106 in the diffuser member 60.

As fluid flows from the reservoir 15, it flows into a chamber 110 whichis defined by the outer peripheral surface of the diffuser member 60.The chamber 110 includes a chamber portion 111 adjacent the projectingportion 101 of the reservoir 15 and into which the fluid from thereservoir 15 initially flows upon detonation of the explosive strip 103.The fluid which flows into the chamber portion 111 is directed by theinternal spherical surface 112 of the diffuser member, which defines, inpart, the chamber portion 111, along the extent of the reservoir 15.

The chamber 110 also includes a generally tapered Chamber portion 115which extends from the chamber portion 111 and which is defined by theouter surface 15a of the reservoir 15 and the inner surface 60a of thediffuser member 60. The chamber portion 115 is tapered to such an extentthat as the fluid flows along the chamber portion 115, it is somewhatcompressed. The taper of the chamber 115 is due to the fact that thereservoir 15 is tapered, while the diffuser member 60 is not, as shownin FIG. 6. The tapered chamber 115 could be provided by otherconstructions including a taper on the diffuser member 60.

The fluid flows into the chamber portion 115 and then flows through theopenings 61 in the diffuser member 60 and into the confinement 12. Thetapered chamber portion 115 provides for substantially the same amountof fluid flow through all the openings 61. There is approximately thesame flow rate through opening 61a which is located farthest from theexplosive 103 as there is through opening 61b which is locatedimmediately adjacent the strip 103. Moreover, the flow of fluid througheach of the openings is maintained substantially equal for a timeinterval so as to provide for a uniform inflation of the confinement asdescribed above in connection with the embodiment described above.

In view of the foregoing, it should be apparent that applicant hasprovided a new and improved safety apparatus for a vehicle and thatcertain changes, modifications, and adaptations may be made therein, andit is intended to cover all such changes, modifications, and adaptationstherein which come within the scope of the appended claims.

What is claimed is:

1. Apparatus comprising first means defining a fluid chamber, saidchamber having different transverse dimensions, said first means havinga thickness which is relatively large where the transverse dimension ofsaid chamber is relatively large and a thickness which is relativelysmall where the transverse dimension of said chamber is relativelysmall, and second means associated with a relatively thin portion ofsaid first means for effecting the formation of an opening therein toprovide for release of fluid from said chamber.

2. Apparatus as defined in claim 1 wherein said second means foreffecting the formation of said opening comprises explosive means.

3. Apparatus as defined in claim 1 wherein said chamber has afrusto-conical shaped portion defined by a portion of said first meanshaving a relatively large thickness and a substantially cylindricalportion defined by a portion of said first means having a relativelysmall thickness.

4. Apparatus as defined in claim 1 further including an expansibleconfinement into which said fluid flows upon release from said chamberto effect inflation of said confinement.

5. Apparatus as defined in claim 4 wherein said second means foreffecting formation of said opening comprises explosive means mounted onsaid relatively thin portion of said first means.

6. Apparatus as defined in claim 5 wherein said explosive meanscomprises a strip of explosive material supported on said relativelythin wall portion.

7. Apparatus for protecting an occupant of a vehicle during a collisioncomprising a confinement having a contracted condition and an inflatedcondition, said confinement when in its inflated condition providing arestraint for controlling movement of an occupant of a vehicle during acollision, a fluid supply having first means defining a fluid chamber,said chamber having different transverse dimensions, said first meanshaving a thickness which is relatively large where the tranversedimension of said chamber is relatively large and a thickness which isrelatively small where the transverse dimension of said chamber isrelatively small, and second means associated with a relatively thinportion of said first means for effecting the formation of an opening insaid relatively thin portion of said first means to provide for releaseof fluid from said chamber for flow into said confinement to effectinflation of said confinement.

8. Apparatus as defined in claim 7 wherein said means for effecting theformation of said opening comprises explosive means mounted on saidrelatively thin portion of said wall means.

9. Apparatus as defined in claim 8 wherein said explosive meanscomprises a strip of explosive material supported on the exterior ofsaid relatively thin portion of said wall means.

10. Apparatus as defined in claim 8 wherein said chamber comprises apair of frusto-conical chamber portions and a substantially cylindricalchamber portion interconnecting said frusto-conical chamber portions,said cylindrical chamber portion being defined by said relatively thinportion of said wall means.

11. Apparatus comprising wall means defining a closed chamber, saidchamber having at least one frusto-conical chamber portion and asubstantially cylindrical chamber portion of an inner diameter less thanthe greatest inner diameter of said frusto-conical chamber portion, saidwall means including a first wall portion defining said frusto-conicalchamber portion, said first wall portion having a trickness whichdecreases as the inner diameter of said frusto-conical chamber portiondecreases, and said wall means including a second wall portion definingsaid cylindrical chamber portion and having a thickness substantiallyless than the greatest thickness of said first wall portion.

12. Apparatus as defined in claim 11 including another frusto-conicalchamber portion, said cylindrical chamber portion interconnecting saidfrusto-conical chamber portions and having an internal diametersubstantially the same as the smallest internal diameter of saidfrustoconical chamber portions.

13. Apparatus as defined in claim 12 wherein the axes of saidfrusto-conical chamber portions and said cylindrical chamber portion lieon a common line.

14. Apparatus for protecting an occupant of a vehicle during a collisioncomprising a confinement having a contracted condition and an inflatedcondition, said confinement when in its inflated condition providing arestraint controlling movement of an occupant of a vehicle during acollision, a fluid supply having wall means defining a closed fluidchamber, said chamber having different transverse dimensions, said wallmeans having a thickness which is relatively large where the transversedimension of said chamber is relatively large and a thickness which isrelatively small where the transverse dimension of said chamber isrelatively small, and means associated with a relatively thin portion ofsaid wall means for effecting the formation of an opening in saidcontainer to provide for release of fluid from said chamber for flowinto said confinement to effect inflation of said confinement, saidrelatively thin portion of said wall means defining a generallycylindrical chamber portion, said relatively thick wall portion of saidchamber defining a frusto-conical chamber portion, and the axes of saidfrusto-conical chamber portion and said cylindrical chamber portionlying on a common line.

15. Apparatus as defined in claim 14 wherein said means for effectingthe formation of said opening comprises explosive means mountedexteriorly of said relatively thin portion of said wall means.

16. Apparatus as defined in claim 15 further including a diffuser meansinterposed between said chamber and said confinement and operable todiffuse the fluid released from said container as it flows into saidconfinement.

17. Apparatus as defined in claim 16 wherein said diffuser means andsaid fluid supply define a chamber therebetween, said chamber having adecreasing flow area as the chamber extends away from the location ofsaid opening, and said diffuser means having passages communicating withsaid chamber at spaced locations along said chamber and through whichsubstantially equal volumes of fluid flow.

18. Apparatus comprising a fluid reservoir for containing a supply offluid, a diffuser member associated with said reservoir, said diffusermember and said reservoir having cooperating surfaces which define achamber therebetween providing a flow path through which fluid from saidreservoir flows, said diffuser member having passages communicating withsaid chamber at spaced locations along said flow path, and said chamberhaving a decreasing flow area as the chamber extends in the direction offluid flow to provide substantially equal volumes of fluid flow throughsaid passages.

19. Apparatus as defined in claim 18 wherein said cooperating surfaceportions include at least one tapered surface providing a chamberportion defined by said diffuser member and said reservoir of agenerally tapered configuration.

20. Apparatus as defined in claim 18 wherein said reservoir has atapered surface portion thereon defining at least a part of saidchamber.

21. Apparatus as defined in claim 18 wherein said flow area decreases inproportion to the decrease in flow of fluid therethrogh to provide asubstantially constant pressure throughout said chamber.

22. Apparatus as defined in claim 21 further including a confinementadapted to be mounted in a vehicle and having an inflated condition,said confinement when in movement of an occupant of a vehicle during acollision.

1 0 References Cited UNITED STATES PATENTS 5/1958 Bertrand 280-1505/1958 Bertrand 280l50 US. Cl. X.R. 220-3

